Prophylactic Antibiotic Therapy and Blood Stream Infections in Leukemia Patients Presenting to the Emergency Center

Abstract

BackgroundPatients undergoing chemotherapy for leukemia are at high risk for infection and routinely receive antibiotic prophylaxis. The types of breakthrough bloodstream infection (BSI) based on choice of prophylaxis is not well-characterized. Here, we describe antibiotic prophylaxis patterns and the influence of antibiotic choice on BSI epidemiology in leukemia patients presenting to the emergency center (EC) with neutropenic fever (NF).MethodsThis was a retrospective chart review of patients with leukemia and NF (absolute neutrophil count [ANC] <500 cells/mm3; temperature ≥38.3°C) who presented to the EC at MD Anderson Cancer Center from January 2014 to January 2015. Patients receiving levofloxacin (LEV), ciprofloxacin (CIP), amoxicillin–clavulanate (ACL), or cefpodoxime (CEF) were included. We assessed current antibiotic prophylaxis at presentation to the EC, and correlated with microbiologically proven bloodstream infections (BSI) within the first 48 hours following presentation.ResultsA total of 284 patients (mean age 56 ± 17 years; 63% male) were assessed. Eighty-four% of patients had neutropenia >7 days in duration and the median ANC at presentation was 0 cells/mm3 (range: 0–490 cells/mm3). Most patients received LEV (42%) followed by CIP (27%), CEF (25%), and ACL (6%). Forty-seven of 284 patients presented with Gram-negative BSI (16%) and 36 (13%) had Gram-positive BSI. Rates of common organisms causing BSI are presented in Table 1.ConclusionIn leukemia patients with NF presenting to the EC, rates of BSI differed significantly based on antibiotic prophylaxis choice, with P. aeruginosa BSI more common in patients receiving ACL and E. coli in patients receiving LEV. The epidemiology of breakthrough infections on different prophylactic agents may help guide empiric antibiotic choice.Table 1.Causative organisms of BSI.BSI TypeLEV (n = 118)CIP (n = 77)CEF (n = 72)ACL (n = 17) P-valueAny Gram-negative (n = 47)21 (18)7 (9)13 (18)6 (35)0.05 E. coli (n = 25)18 (15)3 (4)3 (4)1 (6)0.02 P. aeruginosa (n = 13)2 (2)1 (1)6 (8)4 (24)<0.01Any Gram-positive (n = 36)18 (16)10 (13)7 (10)00.26Alpha-hemolytic Streptococcus (n = 11)4 (4)4 (5)2 (3)00.90 Enterococcus spp. (n = 5)0 (0)2 (3)3 (4)00.12All values presented as n (%).Disclosures R. F. Chemaly, Merck & Co., Inc.: Consultant and Investigator, Consulting fee, Research grant and Speaker honorarium